#pozzolan

[meriol-lehmann]

puy de la vache, saint-genès-champanelle

[meriol-lehmann]

puy de la vache, saint-genès-champanelle

[meriol-lehmann]

puy de la vache, saint-genès-champanelle

[stephenzerbe]

Life is simple

[wtdore]

Riddle solved: Why was Roman concrete so durable?

Researchers have discovered ancient Roman concrete-manufacturing strategies that incorporated self-healing. Applying this knowledge toward m

"Ancient Roman concretes have survived millennia, but mechanistic insights into their durability remain an enigma. Here, we use a multiscale correlative elemental and chemical mapping approach to investigating relict lime clasts, a ubiquitous and conspicuous mineral component associated with ancient Roman mortars. Together, these analyses provide new insights into mortar preparation methodologies and provide evidence that the Romans employed hot mixing, using quicklime in conjunction with, or instead of, slaked lime, to create an environment where high surface area aggregate-scale lime clasts are retained within the mortar matrix. Inspired by these findings, we propose that these macroscopic inclusions might serve as critical sources of reactive calcium for long-term pore and crack-filling or post-pozzolanic reactivity within the cementitious constructs. The subsequent development and testing of modern lime clast–containing cementitious mixtures demonstrate their self-healing potential, thus paving the way for the development of more durable, resilient, and sustainable concrete formulations."

[working-with-rocks]

GeoDog has found an interesting stick and announces that we are to throw it for him.  But he has dropped it on an outcrop of an ash fall tuff that’s become important in the industrial minerals field as a concrete additive. 

[ijtsrd]

Study on Natural Pozzolan as a Partial Replacement for Cement in Pervious Concrete

by Hla Hla Htay | Htet Thu Aung" Study on Natural Pozzolan as a Partial Replacement for Cement in Pervious Concrete" 

Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, 

URL: http://www.ijtsrd.com/papers/ijtsrd15876.pdf 

Direct URL: http://www.ijtsrd.com/engineering/civil-engineering/15876/study-on-natural-pozzolan-as-a-partial-replacement-for-cement-in-pervious-concrete/hla-hla-htay

open access journal of engineering, ugc approved journals for engineering, call for paper engineering

A study on pervious concrete is the balance of permeability and mechanical properties as well as durability. Pervious concrete is important in concrete industry due to the increased awareness of environmental protection. Natural pozzolan is used as a supplementary cementitious material to partially replace of Portland cement in concrete. In this paper mainly focuses on experimental study of different replacement of cement with Popa volcanic natural pozzolan in pervious concrete. This research work is made previous concrete on 10%, 20% by weight replacement of cement with and without pozzolan. 19mm maximum size of crushed gravel was used. Type I Portland cement and water- reducing and retarding concrete admixture were used. Mix design is based on the no slump method from the American Concrete Institute' Committee 211.3R-02. This concrete is tested for its properties, such as density, void content, water permeability and the compressive strength with various ages. According to the results, pozzolan replacement of cement increased as the compressive strength and permeability and durability of pervious concrete decreased.